Tornadoes and Flash Flooding in Iowa, August 31, 2014

Name: Tornadoes and Flash Flooding in Iowa, August 31, 2014
Start: 2014-08-31T17:00
End: 2014-08-31T23:59
Location: Iowa

August 31, 2014 · NWS DMX · 144 events in 26 counties and zones

An unstable airmass was in place across Iowa with afternoon highs reaching well into the 80s, and dewpoint readings in the low to mid 70s. CAPE rose to 2000 to 3000 J/kg.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 1
Property damage: $1.6 million
Crop damage: $575,000
Events: 144

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS DMX wrote it up.

An unstable airmass was in place across Iowa with afternoon highs reaching well into the 80s, and dewpoint readings in the low to mid 70s. CAPE rose to 2000 to 3000 J/kg. Downdraft CAPE was around 900 to 1000 J/kg, with CAPE in the -10 to -30 C layer of the atmosphere in the 600 to 900 J/kg range. Precipitable water increased to around 1.75 inches. The freezing level was quite high at around 15,000 feet. Fairly strong shear was present with 40 to 50 kts of effective shear by late afternoon. A line of thunderstorms formed ahead of the cold front by late afternoon and moved east across the state through the evening hours. Hail with the storms was generally quite small. One inch diameter hail fell in Crawford County in Dow City. The primary severe events from this system were high winds that occurred as the MCS progressed across the state. Several locations reported gusts of 60 MPH or higher. An 80 MPH gust was reported in Guthrie County at Yale and Bayard. A 71 MPH wind gust occurred in Marion County. Heavy rainfall was also of significance with flash flooding in Crawford County. This was caused by a dam failure which flooded Highway 39. Three inches of rain fell in 50 minutes in Dallas County. There were numerous reports of around 2 inches of rain falling in Boone and Polk Counties. Water ponding and low-land flooding was common. One person was struck by lightning at the Denison Airport. The person received minor injuries. Funnel clouds were sighted in both Crawford and Boone Counties. Additional heavy rainfall events are included on 01 September 2014 entry.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before the first event at Aug 31, 3:22 PM CST, 1 hour 38 minutes earlier.

Area forecast discussion, Aug 31, 3:22 PM CST, 1 hour 38 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
422 PM CDT SUN AUG 31 2014

.SHORT TERM /TONIGHT/...
ISSUED AT 422 PM CDT SUN AUG 31 2014

SEVERE WEATHER AND HEAVY RAIN POTENTIAL ARE THE PRIMARY FORECAST
CONCERNS OVERNIGHT. WARM ADVECTION BASED ELEVATED SHOWERS AND
THUNDERSTORMS CURRENTLY ONGOING OVER WESTERN IOWA WITH THE MAIN
FOCUS OVER THE WEST CENTRAL PORTION OF THE STATE. THIS HAS RESULTED
IN AN EXPANSIVE CLOUD DECK OVER CENTRAL IOWA AND HAS LED TO SFC
BASED CAPPING THROUGH THE AREA. THE SFC INSTABILITY IS MUCH STRONGER
INTO SOUTHWEST NEBRASKA AND NORTHEAST KANSAS AND THIS SHOULD BE THE
AREA FOR SURFACE BASED DEVELOPMENT. STORMS MAY BE INITIALLY
SUPERCELLULAR OVER THAT REGION BUT SHOULD GRADUALLY TRANSITION TO A
MORE LINEAR THREAT AS THE SYSTEM ADVANCES INTO WESTERN AND CENTRAL
IOWA. STILL POTENTIAL FOR AN ISOLATED TORNADO THUS THE REASON FOR
THE INCLUSION OF A FEW WESTERN COUNTIES IN THE CURRENT TORNADO
WATCH. THE INSTABILITY AXIS WILL INCREASE ACROSS CENTRAL IOWA AS THE
LOW LEVEL JET INCREASES AND POOLING OF MOISTURE OCCURS AHEAD OF THE
COLD FRONT. A VIGOROUS UPPER LEVEL SHORT WAVE/PV ANOMALY WILL ARRIVE
THIS EVENING WILL HELP STORMS BECOME MORE WIDESPREAD OVERNIGHT.
STORMS INITIALLY SHOULD BE MOVING NEARLY PARALLEL TO THE INSTABILITY
WHICH WILL LEAD TO THE POTENTIAL FOR TRAINING STORMS. DEVELOPING
COLD POOLS AND THE THREAT FOR DAMAGING WIND GUSTS ARE EXPECTED THE
PRIMARY SEVERE WEATHER THREAT.

HEAVY RAINFALL IS ALSO ANOTHER ISSUE OVERNIGHT. CURRENT PWAT VALUES
ARE LESS THAN IMPRESSIVE AND GENERALLY UNDER 1.5 INCHES. HOWEVER
SHOULD HAVE POOLING OVERNIGHT AS ADDITIONAL MOISTURE ARRIVES AND
WILL PUSH VALUES TO NEAR 1.75 INCHES AND WILL HELP LEAD TO FAVORABLE
CONDITIONS FOR WARM RAIN PROCESSES. HAVE ISSUED A FLASH FLOOD WATCH
FOR THE SOUTHWEST QUARTER OF THE AREA WHERE THE LOWEST FLASH FLOOD
GUIDANCE VALUES EXIST IN ADDITION TO THE HIGHEST THREAT FOR HEAVY
RAINFALL. BEST POTENTIAL WILL BE BETWEEN 00-09Z WITH THE DES MOINES
METRO THREAT BETWEEN 03-07Z.

.LONG TERM /MONDAY THROUGH SUNDAY/...
ISSUED AT 405 PM CDT SUN AUG 31 2014

COLD FRONT TO MOVE THROUGH TONIGHT AND BE STRETCHED ACROSS THE FAR
SOUTHEASTERN CWA BY MONDAY MORNING. SOME LINGERING STORMS OR
ADDITIONAL DEVELOPMENT ALONG THE FRONT POSSIBLE THROUGH THE
MORNING/EARLY AFTERNOON HOURS AS SOUTHERLY FLOW AND THETA E
ADVECTION IN PLACE. SECONDARY PUSH OF COOLER AIR ALONG WITH ENERGY
ALOFT TO SLIDE THROUGH NORTHERN IOWA/SOUTHERN MINNESOTA. COULD SEE
SOME CHANCES FOR PRECIP WITH THIS ENERGY AS WELL...BUT MAJORITY OF
PRECIP EXPECTED TO REMAIN NORTH/EAST OF THE CWA. STILL SOME WEAK
INSTABILITY AROUND WITH COOLER AIR MOVING IN ALOFT...AND WEAK
BOUNDARY SO HAVE KEPT SOME SMALL POPS ACROSS THE NORTH/EAST FOR
MONDAY AFTERNOON. ADDITIONAL PRECIPITATION CHANCES EXPECTED ACROSS
NORTHERN IOWA FOR MONDAY NIGHT...AS ANOTHER WEAK WAVE MOVES THROUGH
ALOFT...WITH DRY CONDITIONS EXPECTED TUESDAY INTO EARLY TUESDAY
EVENING AS HIGH PRESSURE BUILDS INTO THE REGION BRIEFLY.

RETURN FLOW SETS UP TUESDAY NIGHT...WITH A WARM FRONT ALOFT LIFTING
NORTH NORTHEAST INTO THE CWA TUESDAY NIGHT. THIS FRONT IS ASSOCIATED
WITH A DEVELOPING AREA OF LOW PRESSURE ALONG THE WESTERN HIGH
PLAINS. MOISTURE TO INCREASE ACROSS THE STATE LATE TUESDAY NIGHT
INTO WEDNESDAY AS SOUTHERLY FLOW INCREASE OFF THE GULF. COULD SEE
SOME THUNDERSTORMS DEVELOP ALONG THE BOUNDARY LIFTING NORTH THROUGH
THE CWA LATE TUESDAY NIGHT INTO WEDNESDAY. DEWPOINTS PUSH INTO 70S
WEDNESDAY...WITH HUMID CONDITIONS RETURNING TO THE CWA. UPPER LEVEL
WAVE TO PUSH EASTWARD FROM THE ROCKIES THROUGH THE CENTRAL US LATE
IN THE WEEK. SFC LOW TO TRACK THROUGH THE GREAT LAKES REGION...WITH
TRAILING COLD FRONT EXPECTED TO DROP THROUGH THE CWA LATE THURSDAY
NIGHT INTO FRIDAY. THIS WILL BRING ADDITIONAL THUNDERSTORM CHANCES
TO THE STATE WITH HIGH PRESSURE AND MAINLY DRY CONDITIONS EXPECTED
INTO THE WEEKEND. EXTENDED RANGE TRYING TO BRING A WEAK SYSTEM
THROUGH LATE IN THE WEEKEND...BUT LOOKS LIKE MAIN TRACK OF THE
SYSTEM WILL BE JUST OFF TO THE NORTH AND EAST FOR NOW. AS FOR
TEMPERATURES...EXPECT WARMING TEMPS MONDAY THROUGH WEDNESDAY WITH
TEMPS NEAR OR ABOVE AVERAGE...WITH A COOL OFF TO SLIGHTLY BELOW
AVERAGE TEMPS FOR THE WEEKEND.

&&

.AVIATION...31/18Z
ISSUED AT 1240 PM CDT SUN AUG 31 2014

BREEZY SOUTHERLY WINDS WILL PREVAIL IN ADVANCE OF A COLD FRONT
WHICH WILL PASS ACROSS THE AREA LATE TONIGHT INTO MONDAY MORNING.
THE PRIMARY AVIATION CONCERN WILL BE WIDESPREAD THUNDERSTORMS
MOVING ACROSS THE STATE OVERNIGHT. STORMS WILL LIKELY HAVE STRONG
WINDS ALONG THE LEADING EDGE AND SIGNIFICANTLY REDUCED
VISIBILITIES IN HEAVY RAIN. A PERIOD OF MVFR STRATUS IS POSSIBLE
BEHIND THE STORMS. THE STRATUS SHOULD BEGINS TO SCATTER AS DRIER
AIR ARRIVES BEHIND THE BOUNDARY.

&&

.HYDROLOGY...
ISSUED AT 1241 PM CDT SUN AUG 31 2014

CONCERNS FOR FLOODING CONTINUE VERY LATE THIS AFTERNOON AND
TONIGHT. CURRENT PROFILES REMAIN QUITE DRY BELOW 700 MB HOWEVER
MOISTURE ADVECTION LATE AFTERNOON AND INTO TONIGHT SHOULD HELP
PUSH PWAT VALUES TO NEAR 1.6 INCHES OVER A NARROW CORRIDOR BY THIS
EVENING. RECENT RAINFALL...ESPECIALLY SOUTHWEST INTO THE CENTRAL
COUNTIES...HAVE PRODUCED NEAR SATURATED GROUND ENOUGH TO LOWER
THE THREE HOUR FFG VALUES TO NEAR 1.5 TO 2.5 INCH RANGE AS A
RESULT OF HIGH RUNOFF RATES. A WIDESPREAD ONE TO TWO INCH
RAINFALL WITH SPOTTY THREE INCH AMOUNTS IS LIKELY OVERNIGHT.
GIVEN THE LOW FFG VALUES...LOCAL FLASH FLOODING IS A POSSIBILITY.
CONTINUE TO MONITOR THE NEED FOR HEADLINES OVERNIGHT.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH MONDAY MORNING FOR ADAIR-ADAMS-AUDUBON-
BOONE-CARROLL-CASS-CLARKE-CRAWFORD-DALLAS-DECATUR-GREENE-GUTHRIE-
MADISON-POLK-RINGGOLD-STORY-TAYLOR-UNION-WARREN.

&&

SHORT TERM...DONAVON
LONG TERM...BEERENDS
AVIATION...DONAVON
HYDROLOGY...MS AUG 14/DONAVON

Hazardous weather outlook, Aug 31, 3:07 PM CST, 1 hour 53 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
407 PM CDT SUN AUG 31 2014

IAZ044>048-057>059-070>073-081>083-092>094-011000-
CRAWFORD-CARROLL-GREENE-BOONE-STORY-AUDUBON-GUTHRIE-DALLAS-CASS-
ADAIR-MADISON-WARREN-ADAMS-UNION-CLARKE-TAYLOR-RINGGOLD-DECATUR-
407 PM CDT SUN AUG 31 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES
FOR FURTHER DETAILS.

THUNDERSTORMS ARE EXPECTED THIS EVENING ACROSS THE AREA. THE
PRIMARY SEVERE THREATS ARE LARGE HAIL AND HIGH WINDS...WITH AN
ISOLATED TORNADO POSSIBLE. HEAVY RAINFALL IS POSSIBLE WITH SOME
STORMS PRODUCING RAINFALL TOTALS OF 1 TO 3 INCHES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS WILL LINGER INTO MONDAY MORNING. ADDITIONAL ROUNDS
OF THUNDERSTORMS ARE EXPECTED LATE TUESDAY NIGHT THROUGH FRIDAY.
THE PROBABILITY OF SEVERE WEATHER IS LOW...WITH THE BEST CHANCE
FOR SEVERE THUNDERSTORMS THURSDAY INTO FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY THIS EVENING INTO TONIGHT.

IAZ060-011000-
POLK-
407 PM CDT SUN AUG 31 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO
THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR
FURTHER DETAILS.

THUNDERSTORMS ARE EXPECTED THIS EVENING ACROSS THE AREA. THE
PRIMARY SEVERE THREATS ARE LARGE HAIL AND HIGH WINDS...WITH AN
ISOLATED TORNADO POSSIBLE. HEAVY RAINFALL IS POSSIBLE WITH SOME
STORMS PRODUCING RAINFALL TOTALS OF 1 TO 3 INCHES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS WILL LINGER INTO MONDAY MORNING. ADDITIONAL ROUNDS
OF THUNDERSTORMS ARE EXPECTED LATE TUESDAY NIGHT THROUGH FRIDAY.
THE PROBABILITY OF SEVERE WEATHER IS LOW...WITH THE BEST CHANCE
FOR SEVERE THUNDERSTORMS THURSDAY INTO FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING INTO TONIGHT.

IAZ004>007-015>017-023>028-033>039-049-050-061-062-074-075-
084>086-095>097-011000-
EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO-
POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN-
WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-MARSHALL-TAMA-JASPER-
POWESHIEK-MARION-MAHASKA-LUCAS-MONROE-WAPELLO-WAYNE-APPANOOSE-
DAVIS-
407 PM CDT SUN AUG 31 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS ARE EXPECTED THIS EVENING ACROSS THE AREA. THE
PRIMARY SEVERE THREATS ARE LARGE HAIL AND HIGH WINDS...WITH AN
ISOLATED TORNADO POSSIBLE. HEAVY RAINFALL IS POSSIBLE WITH SOME
STORMS PRODUCING RAINFALL TOTALS OF 1 TO 3 INCHES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORMS WILL LINGER INTO MONDAY MORNING. ADDITIONAL ROUNDS
OF THUNDERSTORMS ARE EXPECTED LATE TUESDAY NIGHT THROUGH FRIDAY.
THE PROBABILITY OF SEVERE WEATHER IS LOW...WITH THE BEST CHANCE
FOR SEVERE THUNDERSTORMS THURSDAY INTO FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING INTO TONIGHT.

MJB

The radar

The Omaha radar (KOAX), 107 km away, was scanning. The volume nearest the first event began at 23:00 UTC.

Open the radar archive at this moment

Event by event

79 thunderstorm wind, 47 tornado, 8 heavy rain, 7 flash flood, 1 hail, 1 lightning, 1 funnel cloud. Local standard time, as filed.

Heavy Rain, Crawford

When: August 31, 5:00 PM CST to 7:19 PM CST
Where: Crawford County, 1.47 mi NNE of Kenwood
Reported by: Trained Spotter
Coordinates: 42.040, -95.510

Rainfall since 1700 CST was 3.6 inches.

Tornado, Crawford

When: August 31, 5:24 PM CST to 5:42 PM CST
Where: Crawford County, 3.03 mi NNW of Dow City to 3.36 mi NW of Denison Muni Arpt
Rating: EF0
Path length: 5.49 mi
Path width: 330 yd
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 41.969, -95.528

First of many tornadoes to occur on this day. Path was intermittent initially becoming more intense with time. There was video of the parent circulation but path and rating determined by high resolution satellite data.

Tornado, Sac

When: August 31, 5:44 PM CST to 5:50 PM CST
Where: Sac County, 2.28 mi SW of Odebolt to 0.48 mi WNW of Odebolt
Rating: EF0
Path length: 2.13 mi
Path width: 60 yd
Property damage: $90,000
Crop damage: $7,000
Reported by: Other Federal Agency
Coordinates: 42.301, -95.306

This tornado moved northward before encountering a farmstead west of Odebolt. The tornado destroyed 4 grain bins at this site and damage a few augers before taking a 90 degree turn to the east for the remainder of its path. Tornado was found and rated using high resolution satellite imagery.

Hail, Crawford

When: August 31, 5:45 PM CST
Where: Crawford County, 0.51 mi E of Dow City
Measured: 1 in hail
Crop damage: $10,000
Reported by: Public
Coordinates: 41.930, -95.490

Thunderstorm Wind, Crawford

When: August 31, 6:06 PM CST
Where: Crawford County, Denison
Measured: 53 kt (61 mph) estimated gust
Property damage: $5,000
Reported by: Social Media
Coordinates: 42.020, -95.350

Ten inch diameter trees down.

Thunderstorm Wind, Crawford

When: August 31, 6:15 PM CST
Where: Crawford County, Denison
Measured: 55 kt (63 mph) estimated gust
Property damage: $5,000
Reported by: AWOS
Coordinates: 42.020, -95.350

Measured at the Denison AWOS. Multiple trees down and an individual struck by lightning.

Lightning, Crawford

When: August 31, 6:15 PM CST
Where: Crawford County, Denison Muni Arpt
Injuries: 1 direct, 0 indirect
Reported by: Emergency Manager
Coordinates: 41.980, -95.380

One person was injured at the airport by lightning.

Thunderstorm Wind, Crawford

When: August 31, 6:19 PM CST
Where: Crawford County, 1.03 mi W of Denison
Measured: 52 kt (60 mph) estimated gust
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 42.020, -95.370

Campers were tipped over by high winds.

Thunderstorm Wind, Crawford

When: August 31, 6:19 PM CST to 6:20 PM CST
Where: Crawford County, 5.37 mi NW of Aspinwall to 5.41 mi NW of Aspinwall
Measured: 52 kt (60 mph) estimated gust
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 41.972, -95.207

Small miso-vortex associated with large thunderstorm complex in Crawford county. Produced minor to occasionally moderate crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Crawford

When: August 31, 6:21 PM CST
Where: Crawford County, Denison
Measured: 61 kt (70 mph) estimated gust
Property damage: $10,000
Reported by: Public
Coordinates: 42.020, -95.350

The public estimated a wind gust of 70 MPH.

Thunderstorm Wind, Crawford

When: August 31, 6:23 PM CST to 6:24 PM CST
Where: Crawford County, 3.55 mi S of Vail to 4.1 mi SSE of Vail
Measured: 52 kt (60 mph) estimated gust
Crop damage: $3,000
Reported by: Other Federal Agency
Coordinates: 42.019, -95.207

Miso-vortex that produce moderate crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Sac

When: August 31, 6:25 PM CST to 6:26 PM CST
Where: Sac County, 1.69 mi ENE of Carnarvon to 1.82 mi SW of Ulmer
Measured: 52 kt (60 mph) estimated gust
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.257, -94.998

Miso-vortex noted in crop damage in broader strong wind field. Circulation was quite nebulous. Damage was found and documented using high resolution satellite imagery.

Tornado, Crawford

When: August 31, 6:26 PM CST to 6:33 PM CST
Where: Crawford County, 3.95 mi SE of Vail to 2.22 mi SSW of Westside
Rating: EF0
Path length: 2.13 mi
Path width: 200 yd
Crop damage: $10,000
Reported by: NWS Storm Survey
Coordinates: 42.029, -95.147

Three very distinct vortex paths rotating around a common center. These tracks left very well defined paths in crops across eastern Crawford county. Several small miso-vortices were also noted nearby. This tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Carroll

When: August 31, 6:30 PM CST
Where: Carroll County, 0.86 mi NE of Manning
Measured: 56 kt (64 mph) estimated gust
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 41.910, -95.060

Numerous trees were blown down.

Tornado, Carroll

When: August 31, 6:34 PM CST to 6:44 PM CST
Where: Carroll County, 2.99 mi WNW of Halbur to 2.16 mi WSW of Maple River
Rating: EF0
Path length: 4.96 mi
Path width: 90 yd
Crop damage: $7,000
Reported by: Other Federal Agency
Coordinates: 42.023, -95.019

QLCS tornado which moved northward and merged with another tornado just prior to ending. The tornado severly damaged two grain bins along its path. Tornado was found and rated using high resolution satellite imagery.

Tornado, Carroll

When: August 31, 6:38 PM CST to 6:44 PM CST
Where: Carroll County, 2.92 mi N of Halbur to 2.22 mi SW of Maple River
Rating: EF0
Path length: 2.71 mi
Path width: 140 yd
Crop damage: $10,000
Reported by: Other Federal Agency
Coordinates: 42.042, -94.973

QLCS tornado that moved north and merged with another tornado just prior to lifting. Tornado found and rated using high resolution satellite imagery.

Thunderstorm Wind, Carroll

When: August 31, 6:40 PM CST
Where: Carroll County, 0.51 mi E of Templeton
Measured: 56 kt (64 mph) estimated gust
Property damage: $15,000
Reported by: Trained Spotter
Coordinates: 41.920, -94.940

Tree limbs down up to 2 inches in diameter.

Flash Flood, Crawford

When: August 31, 6:42 PM CST to 10:45 PM CST
Where: Crawford County, 2.72 mi N of Denison to 2.93 mi SW of Deloit
Cause: Heavy Rain
Property damage: $250,000
Crop damage: $50,000
Reported by: Emergency Manager
Coordinates: 42.059, -95.352

A dam failure occurred with Highway 39 closed due to flash flooding.

Thunderstorm Wind, Carroll

When: August 31, 6:45 PM CST
Where: Carroll County, 0.86 mi NE of Manning
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.910, -95.060

Tree limbs were blown down.

Tornado, Carroll

When: August 31, 6:45 PM CST to 6:48 PM CST
Where: Carroll County, 2.5 mi E of Carroll to 2.39 mi S of Lidderdale
Rating: EF0
Path length: 3.34 mi
Path width: 200 yd
Crop damage: $10,000
Reported by: Other Federal Agency
Coordinates: 42.073, -94.832

QLCS tornado that began just northeast of Carroll. There were two separate vorticies with a common circulation. Path became intermittent at the end. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Carroll

When: August 31, 6:51 PM CST
Where: Carroll County, 2.42 mi NNW of Mt Carmel to 2.23 mi NNW of Mt Carmel
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.180, -94.924

Small miso-vortex produced minor crop damage. Vortex was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 6:51 PM CST
Where: Calhoun County, 2.48 mi WSW of Wightman to 2.28 mi WSW of Wightman
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.214, -94.694

Very short miso-vortex noted in minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Pocahontas

When: August 31, 6:53 PM CST
Where: Pocahontas County, 0.69 mi N of Pocahontas
Measured: 59 kt (68 mph) measured gust
Reported by: Trained Spotter
Coordinates: 42.740, -94.670

Tornado, Carroll

When: August 31, 6:57 PM CST to 7:02 PM CST
Where: Carroll County, 3.68 mi NE of Glidden to 5.01 mi SE of Lanesboro
Rating: EF0
Path length: 3.05 mi
Path width: 100 yd
Continued into: Greene, Ia (DMX)
Property damage: $2,000
Crop damage: $7,000
Reported by: NWS Storm Survey
Coordinates: 42.109, -94.681

This tornado formed on the leading edge of a QLCS and damaged mostly trees and crops along its path. One small open farm structure was destroyed. A distinct path was noted through corn fields. Track also found and extended into Greene county using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 6:58 PM CST
Where: Calhoun County, 2.07 mi ENE of Wightman to 2.16 mi E of Wightman
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.238, -94.611

Very short miso-vortex evident in crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:00 PM CST to 7:02 PM CST
Where: Calhoun County, 3.61 mi ESE of Wightman to 4.24 mi S of Lohrville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.212, -94.584

Small miso-vortex produced minor crop damage before entering into Greene county. Damage was found and documented using high resolution satellite imagery.

Tornado, Greene

When: August 31, 7:02 PM CST to 7:07 PM CST
Where: Greene County, 5.54 mi N of Ralston to 5.73 mi WSW of Churdan
Rating: EF0
Path length: 2.59 mi
Path width: 75 yd
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.130, -94.629

This is a continuation of a tornado from Carroll county. This tornado remained in rural area of western Greene county doing mainly crop damage. This extension of the path was found and rated using high resolutions satellite imagery.

Thunderstorm Wind, Greene

When: August 31, 7:02 PM CST to 7:05 PM CST
Where: Greene County, 3.26 mi WNW of Adaza to 2.55 mi W of Adaza
Measured: 48 kt (55 mph) estimated gust
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.209, -94.562

This is a continuation of a miso-vortex that began in Calhoun county and entered into northern Greene county. The weak circulation produced only minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:02 PM CST to 7:05 PM CST
Where: Calhoun County, 2.45 mi SSW of Lohrville to 2.94 mi SSE of Lohrville
Measured: 56 kt (64 mph) estimated gust
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.238, -94.570

Miso-vortex was generally weak but had a brief period of more intense circulation along its path. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Guthrie

When: August 31, 7:04 PM CST
Where: Guthrie County, 0.63 mi E of Bayard
Measured: 56 kt (64 mph) estimated gust
Property damage: $15,000
Reported by: Emergency Manager
Coordinates: 41.851, -94.558

Four to ten inch diameter tree branches down.

Thunderstorm Wind, Greene

When: August 31, 7:05 PM CST
Where: Greene County, 5.65 mi W of Adaza to 5.39 mi W of Adaza
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.204, -94.610

Short lived miso-vortex that produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:05 PM CST
Where: Calhoun County, 50.06 mi N of Adair to 49.76 mi N of Adair
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.220, -94.541

Short lived miso-vortex producing only minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:08 PM CST to 7:09 PM CST
Where: Calhoun County, 3.49 mi S of Lohrville to 3.9 mi SSE of Lohrville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.220, -94.541

Another in a series of short lived miso-vorticies that occurred with this thunderstorm complex. Produced only minor crop damage along its path. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Greene

When: August 31, 7:09 PM CST
Where: Greene County, 0.6 mi NW of Adaza to 0.66 mi N of Adaza
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.206, -94.509

Short-lived miso-vortex that produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Greene

When: August 31, 7:10 PM CST
Where: Greene County, 0.34 mi NE of Adaza to 0.98 mi NE of Adaza
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.204, -94.496

Another in a series of short lived miso-vorticies in Greene county. Produced only minor crop damage. The damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:10 PM CST to 7:13 PM CST
Where: Calhoun County, 3.52 mi SE of Lohrville to 5.21 mi SE of Lohrville
Measured: 52 kt (60 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.238, -94.496

Miso-vortex with slightly stronger but broad circulation. Produced a fair amount of crop damage along its path. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:10 PM CST
Where: Calhoun County, 0.99 mi E of Somers to 1.24 mi E of Somers
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.380, -94.411

Short lived miso-vortex the produced minor crop damage. Damage found and documented using high resolution satellite imagery.

Tornado, Greene

When: August 31, 7:11 PM CST to 7:16 PM CST
Where: Greene County, 3.64 mi NNE of Farlin to 4.57 mi W of Paton
Rating: EF0
Path length: 4.49 mi
Path width: 45 yd
Property damage: $1,000
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.127, -94.418

Tornado traveled northeast through Greene county east of Churdan. Encountered a farmstead where a small barn lost its roof. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Greene

When: August 31, 7:11 PM CST to 7:13 PM CST
Where: Greene County, 1.7 mi SE of Churdan to 2.89 mi E of Churdan
Measured: 52 kt (60 mph) estimated gust
Crop damage: $3,000
Reported by: Other Federal Agency
Coordinates: 42.154, -94.455

Miso-vortex with a slightly broader circulation and longer path. Produced minor to moderate crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Audubon

When: August 31, 7:12 PM CST
Where: Audubon County, Audubon
Measured: 50 kt (58 mph) measured gust
Reported by: Mesonet
Coordinates: 41.720, -94.930

Thunderstorm Wind, Guthrie

When: August 31, 7:15 PM CST
Where: Guthrie County, 4.86 mi S of Herndon
Measured: 70 kt (81 mph) estimated gust
Property damage: $50,000
Crop damage: $50,000
Reported by: Law Enforcement
Coordinates: 41.780, -94.360

Power poles broken and lines down.

Thunderstorm Wind, Guthrie

When: August 31, 7:15 PM CST
Where: Guthrie County, 0.51 mi E of Bayard
Measured: 70 kt (81 mph) estimated gust
Property damage: $25,000
Crop damage: $50,000
Reported by: Law Enforcement
Coordinates: 41.850, -94.560

Public estimated wind gusts.

Thunderstorm Wind, Greene

When: August 31, 7:15 PM CST
Where: Greene County, Jefferson
Measured: 52 kt (60 mph) estimated gust
Property damage: $15,000
Reported by: Public
Coordinates: 42.020, -94.380

Trees were blown down in Jefferson.

Thunderstorm Wind, Guthrie

When: August 31, 7:15 PM CST
Where: Guthrie County, 5.84 mi ESE of Fanslers
Measured: 69 kt (79 mph) estimated gust
Property damage: $15,000
Crop damage: $100,000
Reported by: NWS Employee
Coordinates: 41.730, -94.360

Three whole trees of 12 inch diameter snapped. Corn field flattened, with corn laying in same direction.

Tornado, Greene

When: August 31, 7:15 PM CST to 7:19 PM CST
Where: Greene County, 5.22 mi E of Churdan to 3.92 mi NW of Paton
Rating: EF0
Path length: 3.72 mi
Path width: 180 yd
Continued into: Webster, Ia (DMX)
Property damage: $1,000
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.173, -94.378

Tornado traveled northeast through Greene county in rural areas. The tornado did some tree damage to a farmstead but otherwise only produced crop damage before moving into Webster county. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Greene

When: August 31, 7:16 PM CST
Where: Greene County, Jefferson
Measured: 56 kt (64 mph) estimated gust
Property damage: $30,000
Reported by: Law Enforcement
Coordinates: 42.020, -94.380

Numerous reports of trees down and power lines down across the county.

Thunderstorm Wind, Calhoun

When: August 31, 7:16 PM CST to 7:17 PM CST
Where: Calhoun County, 3.75 mi SSW of Farnhamville to 4.03 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.229, -94.423

Another in a series of short lived miso-vorticies with this convective system. Produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:17 PM CST
Where: Calhoun County, 4.28 mi S of Farnhamville to 4.04 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.219, -94.415

Very short miso-vortex produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Guthrie

When: August 31, 7:17 PM CST
Where: Guthrie County, 2.06 mi SSE of Jamaica to 2.28 mi SSE of Jamaica
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 41.821, -94.310

Short lived miso-vortex produced crop damage south of Jamaica. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:18 PM CST to 7:19 PM CST
Where: Calhoun County, 3.53 mi S of Farnhamville to 3.81 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.230, -94.413

Small miso-vortex produced minor crop damage before crossing into Webster county. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:18 PM CST
Where: Webster County, 3.78 mi S of Farnhamville to 3.56 mi SSE of Farnhamville
Measured: 43 kt (49 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.226, -94.387

Very brief miso-vortex that produced only minor crop damage. Damage was found and documented using high resolutions satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:18 PM CST
Where: Webster County, 3.92 mi SSE of Farnhamville to 3.93 mi SSE of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.224, -94.384

Another very brief miso-vortex that produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Tornado, Webster

When: August 31, 7:19 PM CST to 7:25 PM CST
Where: Webster County, 2.7 mi WSW of Lena to 2.98 mi W of Harcourt
Rating: EF0
Path length: 6.07 mi
Path width: 360 yd
Property damage: $1,000
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.209, -94.325

Tornado entered Webster county from Greene county. Tornado continued to head northeast and produced damage to an old grain silo. The tornado circulation weakened and became somewhat ill-defined before taking and hard right turn before dissipating. Tornado was found and rated using high resolution satellite imagery.

Tornado, Webster

When: August 31, 7:19 PM CST to 7:24 PM CST
Where: Webster County, 3.21 mi S of Farnhamville to 0.71 mi SW of Lena
Rating: EF0
Path length: 5.07 mi
Path width: 95 yd
Crop damage: $6,000
Reported by: Other Federal Agency
Coordinates: 42.234, -94.388

Tornado had an intermittent path with moderate to brief areas of extensive crop damage. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:19 PM CST
Where: Webster County, 3.81 mi S of Farnhamville to 3.85 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.225, -94.398

Small miso-vortex which crossed from Calhoun county into Webster county and dissipated shortly thereafter. Only minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Calhoun

When: August 31, 7:19 PM CST
Where: Calhoun County, 2.91 mi S of Farnhamville to 3.18 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.238, -94.401

Another very brief miso-vortex which passed into Webster county. This vortex produced minor crop damage. Damage was found and documented using high resolutions satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:19 PM CST to 7:20 PM CST
Where: Webster County, 3.18 mi S of Farnhamville to 3.64 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.234, -94.398

Miso-vortex crossed from Calhoun county into Webster county. This vortex produced minor crop damage before dissipating. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Guthrie

When: August 31, 7:20 PM CST
Where: Guthrie County, 1.47 mi SSW of Bagley
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.830, -94.440

A tree was blown over at 1247 Quail Road.

Thunderstorm Wind, Webster

When: August 31, 7:20 PM CST
Where: Webster County, 3.54 mi S of Farnhamville to 3.69 mi S of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.229, -94.397

Brief miso-vortex that produce minor crop damage along its path. Damage was found and documented using high resolution satellite imagery.

Tornado, Webster

When: August 31, 7:22 PM CST to 7:25 PM CST
Where: Webster County, 2.46 mi NW of Roberts to 1.69 mi NNW of Roberts
Rating: EF0
Path length: 1.67 mi
Path width: 25 yd
Crop damage: $3,000
Reported by: Other Federal Agency
Coordinates: 42.440, -94.210

Narrow tornado tracked just south of Highway 20 near Fort Dodge. Tornado produce crop damage and crossed Highway 169 before dissipating. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:22 PM CST
Where: Webster County, 3.09 mi SSE of Farnhamville to 3.48 mi SSE of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.242, -94.369

Short lived miso-vortex that produced minor crop damage along its path. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:22 PM CST
Where: Webster County, 3.67 mi SSE of Farnhamville to 3.48 mi SSE of Farnhamville
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.235, -94.361

Very short lived miso-vortex produced minor crop damage along its path. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Webster

When: August 31, 7:23 PM CST
Where: Webster County, 1.31 mi E of Farnhamville
Measured: 60 kt (69 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 42.280, -94.374

Six to ten inch tree limbs were reported down.

Thunderstorm Wind, Webster

When: August 31, 7:23 PM CST
Where: Webster County, 2.49 mi W of Lena to 2.43 mi W of Lena
Measured: 43 kt (49 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.234, -94.328

Another very short lived miso-vortex with minor crop damage. Damage was found and documented using high resolution satellite imagery.

Tornado, Webster

When: August 31, 7:24 PM CST to 7:35 PM CST
Where: Webster County, 2.11 mi W of Lanyon to 2.19 mi WNW of Dayton
Rating: EF0
Path length: 6.42 mi
Path width: 570 yd
Property damage: $2,000
Crop damage: $8,000
Reported by: Other Federal Agency
Coordinates: 42.234, -94.221

Tornado traveled northeast for about half of its life before taking a sharp right turn and moving east southeast for remainder of track. There was some minor damage to grain bins. Tornado was found and rated using high resolution satellite imagery.

Tornado, Webster

When: August 31, 7:26 PM CST to 7:29 PM CST
Where: Webster County, 1.27 mi SSW of Gowrie to 2.19 mi NE of Lena
Rating: EF0
Path length: 2.85 mi
Path width: 400 yd
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.262, -94.306

Tornado traveled east southeast along it entire path and had a broad circulation for much of its life. Very well defined swirls and convergence noted along its path. Tornado was found and rated using high resolution satellite data.

Thunderstorm Wind, Webster

When: August 31, 7:30 PM CST
Where: Webster County, 0.86 mi SE of Harcourt
Measured: 70 kt (81 mph) estimated gust
Property damage: $50,000
Crop damage: $50,000
Reported by: Public
Coordinates: 42.260, -94.170

A garage was destroyed and several trees were downed in town.

Tornado, Dallas

When: August 31, 7:31 PM CST to 7:50 PM CST
Where: Dallas County, 2.89 mi NNW of Panther to 3.13 mi SE of Bouton
Rating: EF0
Path length: 9.48 mi
Path width: 110 yd
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 41.721, -94.114

Longest track tornado of the event remained in rural areas of Dallas county. Only damage was to crops along the path. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Boone

When: August 31, 7:33 PM CST
Where: Boone County, 0.51 mi E of Berkley
Measured: 52 kt (60 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 41.950, -94.110

Estimated gust of 60 MPH.

Tornado, Webster

When: August 31, 7:35 PM CST to 7:41 PM CST
Where: Webster County, 2.42 mi NNW of Dayton to 5.21 mi ENE of Dayton
Rating: EF1
Path length: 5.33 mi
Path width: 100 yd
Property damage: $200,000
Crop damage: $7,000
Reported by: NWS Storm Survey
Coordinates: 42.303, -94.084

This small but potent tornado formed just over 3 miles north of Dayton and tracked nearly due east, destroying one hog confinement building and leaving a pronounced trail through multiple corn fields. The tornado weakened midway into its track, but still left a path 20 yards wide through several other corn fields before doing some minor tree damage at the end of its track. Tornado was surveyed but track lengthened after high resolution satellite imagery showed additional damage and path length.

Funnel Cloud, Boone

When: August 31, 7:38 PM CST
Where: Boone County, 0.51 mi E of Moingona
Reported by: Trained Spotter
Coordinates: 42.020, -93.920

Thunderstorm Wind, Boone

When: August 31, 7:38 PM CST
Where: Boone County, 5.12 mi S of Luther to 4.62 mi WNW of Madrid
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 41.896, -93.950

Minor crop damage produced by miso-vortex. Damage was found and documented using high resolution satellite data.

Thunderstorm Wind, Dallas

When: August 31, 7:39 PM CST
Where: Dallas County, 1.4 mi ESE of Bouton to 1.62 mi ESE of Bouton
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 41.845, -93.994

Well defined miso-vortex that produced crop damage near Bouton. Damage was found and documented using high resolution satellite imagery.

Heavy Rain, Dallas

When: August 31, 7:40 PM CST to 8:10 PM CST
Where: Dallas County, 2.81 mi S of Dawson
Reported by: Public
Coordinates: 41.810, -94.220

Three inches of rain fell in a 50 minute period.

Thunderstorm Wind, Dallas

When: August 31, 7:40 PM CST
Where: Dallas County, 1.24 mi NE of Perry
Measured: 50 kt (58 mph) measured gust
Reported by: ASOS
Coordinates: 41.840, -94.100

Tornado, Webster

When: August 31, 7:40 PM CST to 7:42 PM CST
Where: Webster County, 5.76 mi SE of Lehigh to 6.71 mi ESE of Lehigh
Rating: EF1
Path length: 2.28 mi
Path width: 190 yd
Continued into: Hamilton, Ia (DMX)
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.311, -93.970

Tornado formed about 5 miles southeast of Lehigh and traveled through primarily wooded areas of the Des Moines river valley. Tree damage was noted as well as crop damage in a few fields it crossed through. The tornado then continued on into Hamilton county. Tornado was found and rated using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 7:40 PM CST to 7:47 PM CST
Where: Hamilton County, 0.66 mi ENE of Stratford to 3.87 mi NNW of Stanhope
Rating: EF0
Path length: 5.42 mi
Path width: 90 yd
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.275, -93.919

The tornado formed just northeast of Stratford and moved northeast producing crop and minor tree damage. This tornado merged with another tornado before dissipating. Tornado was found at rated using high resolution satellite imagery.

Thunderstorm Wind, Dallas

When: August 31, 7:41 PM CST
Where: Dallas County, 1.39 mi WNW of Woodward to 1.29 mi NW of Woodward
Measured: 43 kt (49 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 41.861, -93.953

Very short but well defined miso-vortex that produced crop damage. Damage was found and documented using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 7:42 PM CST to 7:45 PM CST
Where: Hamilton County, 3.62 mi S of Homer to 3.39 mi SE of Homer
Rating: EF0
Path length: 2.34 mi
Path width: 205 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.328, -93.932

This tornado entered Hamilton county from Webster county. The tornado continued in rural areas of western Hamilton county producing crop and some tree damage. Tornado was found and rated using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 7:42 PM CST to 7:51 PM CST
Where: Hamilton County, 3.36 mi W of Stanhope to 4.09 mi SW of Kamrar
Rating: EF0
Path length: 6.21 mi
Path width: 280 yd
Property damage: $1,000
Crop damage: $6,000
Reported by: Other Federal Agency
Coordinates: 42.289, -93.865

Tornado developed between Stratford and Stanhope and moved north northeast. The tornado produced mainly crop and minor tree damage with some shingles removed from a house near the track. This tornado merged with another tornado which began near Stratford before ending. Tornado was found and rated using high resolution satellite imagery.

Tornado, Boone

When: August 31, 7:43 PM CST to 7:47 PM CST
Where: Boone County, 2.54 mi WNW of Mackey to 1.08 mi SE of Rosendale
Rating: EF1
Path length: 3.91 mi
Path width: 90 yd
Continued into: Hamilton, Ia (DMX)
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.178, -93.818

This tornado developed in rural northern Boone county and moved northeast. The tornado produce primarily crop damage although did uproot trees when crossing a small creek. This tornado crossed into Hamilton county before dissipating. Tornado was found and rated using high resolution satellite imagery.

Heavy Rain, Boone

When: August 31, 7:45 PM CST to 9:45 PM CST
Where: Boone County, 1.54 mi E of Madrid
Reported by: Public
Coordinates: 41.880, -93.820

Rainfall of 2.35 inches in the past 2 hours.

Tornado, Hamilton

When: August 31, 7:46 PM CST to 7:52 PM CST
Where: Hamilton County, 1.52 mi NE of Stanhope to 3.58 mi NW of Jewell
Rating: EF0
Path length: 5.24 mi
Path width: 65 yd
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.295, -93.779

Tornado develop about 1 mile northeast of Stanhope and moved northeast. The tornado did produce some minor tree damage along with crop damage along its path. The tornado was quite narrow but broadened considerably prior to its dissipation. Tornado was found and rated using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 7:47 PM CST to 7:49 PM CST
Where: Hamilton County, 1.91 mi WSW of Rosedale to 0.61 mi N of Rosedale
Rating: EF0
Path length: 2.24 mi
Path width: 30 yd
Property damage: $1,000
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.209, -93.754

This tornado moved into Hamilton county from Boone county. The tornado narrowed its path in Hamilton county producing crop damage and destroying a lean-to before dissipating. The tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Dallas

When: August 31, 7:50 PM CST
Where: Dallas County, 0.86 mi SW of Adel
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: Emergency Manager
Coordinates: 41.610, -94.030

A large tree was downed on a power line.

Tornado, Hamilton

When: August 31, 7:50 PM CST to 7:51 PM CST
Where: Hamilton County, 4.28 mi SW of Kamrar to 3.86 mi SSW of Kamrar
Rating: EF0
Path length: 1.35 mi
Path width: 60 yd
Property damage: $95,000
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.359, -93.793

Brief tornado formed about 4 miles southwest of Kamrar and moved east southeast for its entire length. The tornado destroyed 3 grain bins at a farmstead along with crop damage. Tornado was found and rated using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 7:52 PM CST to 7:54 PM CST
Where: Hamilton County, 2.6 mi SW of Kamrar to 2.2 mi S of Kamrar
Rating: EF0
Path length: 1.73 mi
Path width: 340 yd
Property damage: $75,000
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.370, -93.761

Brief tornado developed about 2.5 miles southwest of Kamrar and moved east southeast. This tornado took part of the roof off a confinement building along with crop damage along its path. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Dallas

When: August 31, 7:55 PM CST
Where: Dallas County, 0.52 mi W of Dallas Center
Measured: 52 kt (60 mph) estimated gust
Property damage: $10,000
Reported by: Trained Spotter
Coordinates: 41.680, -93.980

Ten to twelve inch tree limbs were blown down.

Thunderstorm Wind, Dallas

When: August 31, 7:56 PM CST
Where: Dallas County, 3.06 mi N of Dallas Center
Measured: 52 kt (60 mph) estimated gust
Reported by: Amateur Radio
Coordinates: 41.724, -93.970

Located at R16 and 215TH Street.

Thunderstorm Wind, Hamilton

When: August 31, 7:57 PM CST
Where: Hamilton County, 2.2 mi SSW of Ellsworth to 1.67 mi SSW of Ellsworth
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.292, -93.601

Broad wind field, especially on south side of miso-vortex. Produced minor crop damage along its path. Damage was found and documented using high resolutions satellite imagery.

Thunderstorm Wind, Cerro Gordo

When: August 31, 7:57 PM CST to 7:58 PM CST
Where: Cerro Gordo County, 6.72 mi N of Clear Lake Lake to 7.17 mi N of Clear Lake Lake
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 43.247, -93.423

Miso-vortex in northern Cerro Gordo county produced crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Dallas

When: August 31, 7:58 PM CST
Where: Dallas County, 1.03 mi W of Dallas Center Arpt
Measured: 52 kt (60 mph) estimated gust
Reported by: Amateur Radio
Coordinates: 41.680, -94.040

Estimated wind of 60 MPH.

Thunderstorm Wind, Dallas

When: August 31, 7:58 PM CST
Where: Dallas County, 3.45 mi N of Dallas Center
Measured: 71 kt (82 mph) estimated gust
Property damage: $25,000
Reported by: Trained Spotter
Coordinates: 41.730, -93.970

Power poles were snapped in half by high winds.

Tornado, Hamilton

When: August 31, 7:58 PM CST to 8:03 PM CST
Where: Hamilton County, 4.69 mi E of Kamrar to 4.29 mi SSW of Williams
Rating: EF0
Path length: 3.72 mi
Path width: 60 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.395, -93.638

Narrow tornado formed about 4.5 miles east of Kamrar and moved northeast. The tornado remained in open farmland for the duration of its life producing only damage to crops. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hamilton

When: August 31, 7:59 PM CST to 8:04 PM CST
Where: Hamilton County, 3.16 mi NNW of Ellsworth
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Public
Coordinates: 42.360, -93.610

Large trees down and power pole snapped. Winds lasted 5 minutes.

Tornado, Hamilton

When: August 31, 7:59 PM CST to 8:01 PM CST
Where: Hamilton County, 5.03 mi N of Blairsburg to 5.42 mi N of Blairsburg
Rating: EF0
Path length: 1.18 mi
Path width: 60 yd
Continued into: Wright, Ia (DMX)
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.553, -93.637

Tornado formed nearly 5 miles north of Blairsburg and travel northeast in rural farmland producing only crop damage. This tornado then moved into Wright county. The tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hamilton

When: August 31, 8:00 PM CST
Where: Hamilton County, 1.23 mi SE of Ellsworth
Measured: 52 kt (60 mph) estimated gust
Reported by: Trained Spotter
Coordinates: 42.310, -93.560

Wind gusts of 60 MPH were reported.

Tornado, Wright

When: August 31, 8:01 PM CST to 8:07 PM CST
Where: Wright County, 8.49 mi S of Galt to 5.05 mi S of Dows
Rating: EF0
Path length: 5.86 mi
Path width: 170 yd
Property damage: $25,000
Crop damage: $7,000
Reported by: Other Federal Agency
Coordinates: 42.558, -93.615

This tornado moved into Wright county from Hamilton county. The tornado continued to travel east northeast in rural areas of southern Wright county producing mainly crop damage. It did destroyed two empty grain bins before dissipating. The tornado was found and rated using high resolution satellite imagery.

Tornado, Bremer

When: August 31, 8:01 PM CST to 8:03 PM CST
Where: Bremer County, 4.26 mi WSW of Babcock to 2.4 mi W of Janesville
Rating: EF0
Path length: 1.89 mi
Path width: 70 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.652, -92.555

This tornado produced crop damage as it moved to the east. Another tornado crossed its path. Tornado was found and rated using high resolution satellite imagery.

Heavy Rain, Boone

When: August 31, 8:03 PM CST to 9:48 PM CST
Where: Boone County, 1.54 mi E of Madrid
Reported by: Public
Coordinates: 41.880, -93.820

Rainfall in the past hour and 45 minutes.

Thunderstorm Wind, Story

When: August 31, 8:05 PM CST
Where: Story County, Roland
Measured: 52 kt (60 mph) estimated gust
Reported by: Emergency Manager
Coordinates: 42.170, -93.500

Wind gust estimated at 60 MPH.

Tornado, Hamilton

When: August 31, 8:06 PM CST to 8:07 PM CST
Where: Hamilton County, 3.05 mi SSE of Williams to 3.92 mi SE of Williams
Rating: EF0
Path length: 1.15 mi
Path width: 50 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.443, -93.518

This brief and narrow tornado formed a little over 3 miles southeast of Williams and moved east southeast. It remained in open farmland producing some crop damage. The tornado was found and rated using high resolution satellite imagery.

Tornado, Franklin

When: August 31, 8:07 PM CST to 8:10 PM CST
Where: Franklin County, 2.96 mi WNW of Oakland to 1.03 mi WNW of Popejoy
Rating: EF0
Path length: 2.41 mi
Path width: 75 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.595, -93.484

Tornado formed nearly 3 miles west of Popejoy and moved east northeast for the duration of the tornado. The tornado remained in rural areas of Franklin county producing minor crop damage. The tornado was found and rated using high resolution satellite imagery.

Tornado, Hamilton

When: August 31, 8:08 PM CST to 8:09 PM CST
Where: Hamilton County, 3.84 mi SE of Williams to 3.41 mi S of Wilke
Rating: EF0
Path length: 1.5 mi
Path width: 50 yd
Continued into: Hardin, Ia (DMX)
Property damage: $10,000
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.445, -93.491

Tornado formed 4 miles southeast of Williams and moved initially north but made a sweeping right turn to the east southeast before leaving the county. An outbuilding lost part of its roof with crop damage occurring along the path. The tornado then entered Hardin county. The tornado was found and rated using high resolution satellite imagery.

Tornado, Hardin

When: August 31, 8:09 PM CST to 8:10 PM CST
Where: Hardin County, 4.73 mi WNW of Buckeye to 3.62 mi WNW of Buckeye
Rating: EF1
Path length: 1.13 mi
Path width: 150 yd
Property damage: $100,000
Crop damage: $5,000
Reported by: Other Federal Agency
Coordinates: 42.451, -93.463

This tornado moved into Hardin county from Hamilton county. This short segment did primarily crop damage but hit a farmstead before dissipating causing the destruction of two grain bins and badly damaging three outbuildings. This tornado was found and rated using high resolution satellite imagery.

Tornado, Hardin

When: August 31, 8:11 PM CST to 8:13 PM CST
Where: Hardin County, 3.68 mi NW of Buckeye to 3.19 mi N of Buckeye
Rating: EF0
Path length: 2.17 mi
Path width: 60 yd
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.464, -93.422

This short lived and narrow tornado remained in rural areas of western Hardin county producing only crop damage. The tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hardin

When: August 31, 8:15 PM CST to 8:16 PM CST
Where: Hardin County, 3.73 mi NNE of Buckeye to 3.26 mi W of Iowa Falls Muni Arpt
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.470, -93.353

Miso-vortex produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Tornado, Hardin

When: August 31, 8:18 PM CST to 8:19 PM CST
Where: Hardin County, 1.57 mi W of Iowa Falls Muni Arpt to 0.22 mi WNW of Iowa Falls Muni Arpt
Rating: EF0
Path length: 1.39 mi
Path width: 200 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.469, -93.301

This short lived tornado occurred just west of the Iowa Falls Airport. The circulation was broad for the duration of the tornado but swirls were very evident in the damage pattern across the agricultural fields. This tornado was found and rated using high resolution satellite imagery.

Tornado, Hardin

When: August 31, 8:18 PM CST to 8:19 PM CST
Where: Hardin County, 2.15 mi WSW of Owasa to 1.45 mi WNW of Owasa
Rating: EF1
Path length: 1.55 mi
Path width: 150 yd
Property damage: $25,000
Crop damage: $4,000
Reported by: Other Federal Agency
Coordinates: 42.419, -93.239

Tornado formed 2 miles southwest of Owasa immediately hitting a farmstead destroying a grain bin and uprooting several trees. The tornado then travel across open farmland for the remainder of its path. The tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hardin

When: August 31, 8:18 PM CST to 8:19 PM CST
Where: Hardin County, 1.61 mi W of Iowa Falls Muni Arpt to 0.51 mi WSW of Iowa Falls Muni Arpt
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.468, -93.301

Miso-vortex just west of the Iowa Fall Airport produced minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Hardin

When: August 31, 8:19 PM CST
Where: Hardin County, 0.8 mi SE of Iowa Falls Muni Arpt to 1.16 mi E of Iowa Falls Muni Arpt
Measured: 48 kt (55 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.462, -93.258

Short lived miso-vortex occurred just southeast of Iowa Falls Airport producing only minor crop damage. Damage was found and documented using high resolution satellite imagery.

Thunderstorm Wind, Dallas

When: August 31, 8:20 PM CST
Where: Dallas County, 4.18 mi S of Moran
Measured: 56 kt (64 mph) measured gust
Property damage: $5,000
Reported by: Public
Coordinates: 41.760, -93.930

Tornado, Adair

When: August 31, 8:23 PM CST to 8:24 PM CST
Where: Adair County, 4.44 mi N of Arbor Hill to 4.88 mi NNE of Arbor Hill
Rating: EF0
Path length: 0.86 mi
Path width: 50 yd
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 41.433, -94.305

Tornado formed as broader wind field narrowed into a circulation in northern Adair county. Tornado produced only crop damage along its relatively short path. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hardin

When: August 31, 8:25 PM CST
Where: Hardin County, 0.51 mi E of Iowa Falls Muni Arpt
Measured: 57 kt (66 mph) measured gust
Property damage: $5,000
Reported by: AWOS
Coordinates: 42.470, -93.260

Thunderstorm Wind, Polk

When: August 31, 8:25 PM CST
Where: Polk County, 0.81 mi S of Urbandale
Measured: 52 kt (60 mph) estimated gust
Property damage: $3,000
Reported by: Public
Coordinates: 41.618, -93.721

Limbs were blown off of trees.

Thunderstorm Wind, Story

When: August 31, 8:26 PM CST
Where: Story County, Slater
Measured: 52 kt (60 mph) estimated gust
Property damage: $5,000
Reported by: NWS Employee
Coordinates: 41.880, -93.680

Several tree limbs down in town.

Thunderstorm Wind, Hardin

When: August 31, 8:34 PM CST
Where: Hardin County, 1.72 mi SW of Cleves
Measured: 52 kt (60 mph) measured gust
Reported by: Mesonet
Coordinates: 42.450, -93.070

Tornado, Grundy

When: August 31, 8:35 PM CST to 8:37 PM CST
Where: Grundy County, 7.21 mi NW of Wellsburg to 8.08 mi NNW of Wellsburg
Rating: EF0
Path length: 1.66 mi
Path width: 75 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.513, -93.005

Produced only crop damage along its path. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Hardin

When: August 31, 8:36 PM CST
Where: Hardin County, 0.69 mi S of Steamboat Rock
Measured: 52 kt (60 mph) measured gust
Reported by: Mesonet
Coordinates: 42.410, -93.070

Recorded at a mesonet site.

Tornado, Butler

When: August 31, 8:39 PM CST to 8:42 PM CST
Where: Butler County, 1.97 mi SW of Aplington to 0.19 mi SE of Aplington
Rating: EF0
Path length: 1.96 mi
Path width: 55 yd
Property damage: $20,000
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.556, -92.902

This tornado moved northeast and grazed the southeast corner of Aplington, hitting a farmstead on the edge of town. Two outbuildings were severly damaged and trees were uprooted. This tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Grundy

When: August 31, 8:40 PM CST
Where: Grundy County, Wellsburg
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Amateur Radio
Coordinates: 42.430, -92.920

Minor tree damage reported.

Thunderstorm Wind, Grundy

When: August 31, 8:41 PM CST
Where: Grundy County, 5.67 mi N of Wellsburg
Measured: 60 kt (69 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 42.512, -92.928

One to two foot diameter tree down. Six to 10 inch diameter tree limbs downed and one tree limb landed on power lines taking them down too.

Thunderstorm Wind, Grundy

When: August 31, 8:45 PM CST
Where: Grundy County, 2.93 mi NW of Holland
Measured: 61 kt (70 mph) estimated gust
Property damage: $100,000
Crop damage: $25,000
Reported by: Trained Spotter
Coordinates: 42.424, -92.847

At 9:45 p.m on 8/31 in Grundy County, Iowa just south of County HWY D25 on J Ave our farm lost 3/4 of it's machine shed roof on the SE side. Part of the roof landed straight east short of 300 ft to 400 ft down driveway and the other part west in front of the shed but on the NE side. More steel was to the NE about 300 ft to 400 ft and just missed our house. The steel bent over the cable dish. There was insulation splattered all over the garage and house to the NE of where roof went off and both garage doors were damaged.

Thunderstorm Wind, Polk

When: August 31, 8:49 PM CST
Where: Polk County, 0.85 mi WSW of Altoona
Measured: 56 kt (64 mph) estimated gust
Property damage: $3,000
Reported by: Trained Spotter
Coordinates: 41.647, -93.486

Spotter estimated 65 mph wind gust.

Tornado, Butler

When: August 31, 8:49 PM CST to 8:52 PM CST
Where: Butler County, 2.2 mi NNE of Parkersburg to 1.81 mi W of Swanton
Rating: EF0
Path length: 2.2 mi
Path width: 85 yd
Crop damage: $3,000
Reported by: Other Federal Agency
Coordinates: 42.601, -92.770

Track meandered to the northeast with only crop damage noted. This tornado likely merged with another tornado before dissipating. Tornado was found and rated using high resolution satellite imagery.

Tornado, Butler

When: August 31, 8:51 PM CST to 8:53 PM CST
Where: Butler County, 1.92 mi SW of New Albion to 1.04 mi WNW of Swanton
Rating: EF0
Path length: 1.71 mi
Path width: 65 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.627, -92.751

Produced crop damage and the likely merged with another tornado before dissipating. Tornado was found and rated using high resolution satellite imagery.

Thunderstorm Wind, Butler

When: August 31, 8:53 PM CST
Where: Butler County, 1.43 mi SE of Swanton to 1.46 mi SE of Swanton
Measured: 52 kt (60 mph) estimated gust
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.604, -92.682

Very short but somewhat intense miso-vortex produced crop damage. Damage was found and documented using high resolution satellite imagery.

Tornado, Butler

When: August 31, 9:00 PM CST to 9:01 PM CST
Where: Butler County, 4.82 mi SSE of Shell Rock to 4.88 mi SSE of Shell Rock
Rating: EF0
Path length: 0.21 mi
Path width: 50 yd
Continued into: Bremer, Ia (DMX)
Crop damage: $1,000
Reported by: Other Federal Agency
Coordinates: 42.652, -92.559

This tornado developed and quickly moved out of the county and into Bremer county. Only crop damage was noted with this segment of the tornado. Tornado was found and rated using high resolution satellite imagery.

Tornado, Bremer

When: August 31, 9:02 PM CST to 9:03 PM CST
Where: Bremer County, 3.45 mi W of Janesville to 2.93 mi WSW of Babcock
Rating: EF0
Path length: 0.76 mi
Path width: 85 yd
Property damage: $1,000
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.649, -92.538

This tornado crossed the path of another tornado and then hit a farmstead, doing some minor tree damage. Crop damage was also noted along its path. Tornado was found and rated using high resolution satellite imagery.

Tornado, Black Hawk

When: August 31, 9:04 PM CST to 9:07 PM CST
Where: Black Hawk County, 3.49 mi ENE of Farmer to 3.31 mi WNW of Boies
Rating: EF0
Path length: 2.07 mi
Path width: 130 yd
Property damage: $1,000
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.617, -92.466

This tornado moved northeast on the southeast edge of Janesville. This tornado produced primarily crop damage with some minor tree damage.

Flash Flood, Dallas

When: August 31, 9:06 PM CST to 11:00 PM CST
Where: Dallas County, 2.49 mi SE of Perry to 3.81 mi NE of Shuler Mine
Cause: Heavy Rain
Property damage: $50,000
Reported by: Emergency Manager
Coordinates: 41.802, -94.090

Numerous locations on Highway 44 throughout the county have water over the road, in some places 6 to 8 inches deep. Highway 169 north of Minburn had water over the road.

Flash Flood, Dallas

When: August 31, 9:08 PM CST
Where: Dallas County, Minburn to 2.04 mi E of Minburn
Cause: Heavy Rain
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 41.770, -94.030

Water was reported running over HWY 169 several inches deep.

Tornado, Black Hawk

When: August 31, 9:12 PM CST to 9:17 PM CST
Where: Black Hawk County, 3.1 mi ESE of Boies to 2.72 mi SW of Dunkerton Davis Arpt
Rating: EF0
Path length: 3.22 mi
Path width: 80 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.597, -92.328

Tornado moved across northern Black Hawk county and produced crop damage. Tornado was found and rated using high resolution satellite imagery.

Heavy Rain, Polk

When: August 31, 9:14 PM CST
Where: Polk County, 0.86 mi NW of Carney
Reported by: Trained Spotter
Coordinates: 41.690, -93.610

Rainfall just short of 2 inches.

Heavy Rain, Polk

When: August 31, 9:15 PM CST
Where: Polk County, 2.07 mi S of Polk City
Reported by: NWS Employee
Coordinates: 41.740, -93.720

Rainfall of 1.82 inches reported at the NWS in Johnston.

Tornado, Bremer

When: August 31, 9:17 PM CST to 9:24 PM CST
Where: Bremer County, 1.22 mi SW of Knittel to 2.7 mi ENE of Readlyn
Rating: EF0
Path length: 5.41 mi
Path width: 100 yd
Crop damage: $2,000
Reported by: Other Federal Agency
Coordinates: 42.709, -92.289

Tornado which moved eastward and producing crop damage. Tornado moved north of the town of Readlyn before dissipating. Tornado was found and rated using high resolution satellite imagery.

Flash Flood, Dallas

When: August 31, 9:20 PM CST to 11:00 PM CST
Where: Dallas County, 4.36 mi ESE of Minburn to 4.16 mi WSW of Dallas Mine
Cause: Heavy Rain
Property damage: $50,000
Reported by: Trained Spotter
Coordinates: 41.746, -93.952

Water several feet deep over F31.

Flash Flood, Warren

When: August 31, 9:30 PM CST to 11:00 PM CST
Where: Warren County, 0.17 mi SSW of Norwalk to 0.19 mi WSW of Norwalk
Cause: Heavy Rain
Property damage: $5,000
Reported by: Amateur Radio
Coordinates: 41.478, -93.682

Three feet of standing water was reported over the road.

Flash Flood, Polk

When: August 31, 9:43 PM CST to 11:00 PM CST
Where: Polk County, 0.69 mi S of Ft Des Moines to 1.04 mi SE of Ft Des Moines
Cause: Heavy Rain
Property damage: $75,000
Reported by: Fire Department/Rescue
Coordinates: 41.520, -93.630

A report that southwest 9th and Luster Lane had two stalled cars with water 6 inches deep.

Thunderstorm Wind, Jasper

When: August 31, 9:48 PM CST
Where: Jasper County, 2.59 mi SW of Prairie City
Measured: 51 kt (59 mph) measured gust
Reported by: Mesonet
Coordinates: 41.570, -93.260

Heavy Rain, Polk

When: August 31, 9:50 PM CST
Where: Polk County, 0.69 mi N of Grimes
Reported by: Trained Spotter
Coordinates: 41.690, -93.800

Little Beaver Creek was reported to be bankful.

Flash Flood, Polk

When: August 31, 9:50 PM CST to 11:00 PM CST
Where: Polk County, 1.25 mi S of Saydell to 1.38 mi SSE of Saydell
Cause: Heavy Rain
Property damage: $5,000
Reported by: Amateur Radio
Coordinates: 41.652, -93.623

Three feet of standing water was reported over the road at the intersection of NE 5th and NE 50th in Saylor Township.

Thunderstorm Wind, Marion

When: August 31, 10:05 PM CST
Where: Marion County, 0.52 mi E of Knoxville Arpt
Measured: 62 kt (71 mph) measured gust
Property damage: $10,000
Reported by: AWOS
Coordinates: 41.300, -93.110

Heavy Rain, Polk

When: August 31, 11:59 PM CST
Where: Polk County, 0.3 mi NNE of Windsor Hgts
Reported by: NWS Employee
Coordinates: 41.604, -93.718

Rainfall of 2.03 inches.

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Lightning: A lightning strike that killed, injured or caused damage.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Funnel Cloud: A rotating column of cloud extending from a thunderstorm that did not reach the ground.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Iowa in 2014 Every state in 2014 This day in weather history The tornado archive for Iowa, 2014 Warnings in Iowa, August 2014

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 531696, 603517, 603927, 531695, 540752, 531712, 531724, 531725, 604369, 531727, 604370, 604375, 603518, 531730, 603519, 603520, 531729, 531689, 531726, 603521, 604372, 604386, 531704, 533460, 604387, 604388, 603926, 604389, 604390, 540758, 604378, 604447, 604448, 604380, 604381, 604449, 604454, 603928, 604383, 531705, and more.